Polyamine materials have been widely used in many areas ranging from commodity industry applications to home-and-personal care and pharmaceutical uses largely due to their cationic and hydrogen bonding properties. The cationic and the hydrogen bonding characteristics are given by the amine functionality and are modulated by the amine content, which also dictates the charge density on the material. In many applications, higher amine content leads to higher efficacy.
To date, known polyamines with high amine content include polyvinyl amines and polyethyleneimines, which both possess one amine group for every two carbon units (amine/carbon ratio=½), and polyallylamines, which possesses one amine group for every three carbon units (amine/carbon ratio=⅓). Polyvinyl amine is usually made from free-radical polymerization of vinyl formamide followed by hydrolysis of the formamide groups. It is a linear polymer comprising a polyethylene backbone with pendant primary amines. Polyethyleneimines produced by ring-opening polymerization of aziridines results in a hyperbranched structure with a mixed carbon and nitrogen backbone containing a mixture of primary, secondary, and tertiary amines. Linear polyethyleneimine is produced by ring opening polymerization of oxazolidine derivatives. The chemically different amines in these two materials are notable since the primary amine having the high reactivity is often utilized for further cross-linking and derivatization of the material.
Although these two materials have been widely used, higher amine content materials and alternative compounds are still highly desired.